Study on Double Range Neutron Fluence Rate Detector

At the initial stage of reactor start-up, the neutron fluence is very low, so there exists certain blind area for a general nuclear measurement system. A double probe neutron fluence rate detector was designed which has a wide range and high sensitivity for the measurement of the blind area. The calculation and experiment results show that the double detector works stably and provides a method of measuring very low neutron fluence rate in the process of reactor physical start-up.